Leaking grout/tiles on spa waterfall

[JohnM58]

Newcomer here. I have a question about my spa overflow waterfall is constructed.

There are three steps on the waterfall, all tile/grout on the vertical and horizontal surfaces.
I lose 500 gallons per week. I have isolated it to the waterfall itself. I've conducted several bucket tests, pressure tests, etc. The leak is present when water is running over the waterfall, even when it's just a garden hose with no pressure in the system. The leak is not present when water is running across a liner on top of the waterfall.

I have regrouted, and applied grout sealer, but it has made very little difference.
There are no cracks in the tile, but I suspect if I tear out the tile, I will find cracks underneath in the concrete base.

Questions:

If I were to tear out and replace the tile, how can I ensure I fix the leak? What is the best material to use to seal cracks in the concrete?
Are tile waterfalls sometimes built like tile shower stalls using some type of lead, rubber, or plastic liner?

I may decide to remove the tile and replace it with a tumbled stone creek looking arrangement, but whatever I do I want to be sure the leak is sealed.

Thanks for any thoughts.

 

[duraleigh]

Hi, John,

Welcome to the forum. :lol: 70 gallons daily is more than just seepage through the grout. I would bet you have a break in the surface somewhere and, if that's the case, perhaps it can be sealed and not have to remove the tile. Do you have a picture?

 

[JohnM58]

I'm confident there are no major breaks. As I understand it, grout is not waterproof, but it still shouldn't leak 70 gallons per day. I suspect the grout on the side walls leaks like a sieve, there may be large cracks between the stones but under the grout. When I regrouted the tile, I did not remove the grout on the sides. It is about 1/2 inch thick in some places on top of the stone, chiseling it off was damaging the stone.

Actually it's 70 gallons over six hours, which is the daily runtime on the filter pump right now. When the pump is not running, there is no leak.

Below is the spa overflow that leaks. The plastic liner is siliconed across the top, which is why it's still in the picture. When the water runs across the plastic there is no leak.

[attachment=1:2os1fq3z]20130217_162224b.JPG[/attachment:2os1fq3z]

Below is the outside rock wall below the waterfall, when water is flowing across the tile, (whether from the filter pump, or a garden hose) the leak is visible on the lower part of the wall. It is not just wet, it is visibly running down the wall and puddles on the ground. I initially thought it most likely to be a pressurized waterline inside the spa, something that leaked while under pressure, but did not leak with no pressure. The spa does not drain down to the jets when the pump is off.

[attachment=0:2os1fq3z]20130217_162152b.JPG[/attachment:2os1fq3z]

 

[duraleigh]

So the water comes from where the plastic is in the picture, cascades over the blue tile and into the pool and it leaks 70 gallons in six hours.

I know you are there in person and can see it better than me but, for the life of me, I can't understand why you don't discover what has to be a VERY LARGE passage for water to get through.

I would bring in another set of eyes before I tore up the tile. Sometimes another person will detect something you have overlooked.

 

[JohnM58]

Thanks for the replies. Yes it has been a puzzle. Other sets of eyes have looked at it, but I have not asked a pool builder to look at it. The only thing certain is that you can easily see where the water is coming out, it runs about three cups per minute. The challenge has been in finding where it comes from. When water cascades over the blue tile, water runs out of the rocks below. When water cascades over the plastic, the rocks below are bone dry.

This is why I'm asking about how these spa overflows are typically built. I imagine mine is not built with a PVC liner like in a shower pan. If I were to rebuild it, should I look for a PVC liner? Build one of my own? Or are these overflows sealed some other way?

 

[duraleigh]

If I were to rebuild it, should I look for a PVC liner? Build one of my own? Or are these overflows sealed some other way?

Go to johnhbridge.com and search in their tile forum for "Kerdi" systems.

It essentially incorporates a felt-like waterproof membrane into thinset and then the tile is laid onto another thinset layer above that. I used it in a shower and it is absolutely waterproof. Any shower pan membrane will work, too but this one struck me as the best for sealing corners and odd angled surfaces.

 

[heikejohn]

With the pressure on, the water might squirt into places you can't see. Like into a crevice that is right before the water is coming out to spill over the tile.

 

[JohnM58]

Duraleigh, thanks, the kerdi tiling membrane looks like it's exactly what I need.
Seems like something that should have been used when the pool was built in the first place.
I'm guessing either there is no liner present, or it has a major failure. The pool is about ten years old.

heikejohn, good thought, but the leak is present when the pump is off and I'm only using a garden hose to fill and overflow the spa. Although it leaks at a much lower rate with the garden hose, there's a lot less water flowing over the waterfall compared to when the filter pump is running.